查看文章

Laser ablation in liquid was utilized to prepare a TiO₂ NP suspension in in deionized distilled water using Q-switch Nd: YAG laser at various laser energies and ablation times. The samples were characterized using UV–visible absorption spectra obtained with a UV–visible spectrophotometer (UV-Vis,) Fourier transform infrared (FTIR), X-ray diffraction (XRD), and transmission electron microscope (TEM). While, UV-Vis spectra showed the characteristic band-to-band absorption peak of TiO₂ NPs in the UV range. FTIR analysis showed the existence of O-Ti-O bond. XRD patterns indicated the presence of (101) and (112) plane crystalline phases of TiO₂. TEM images showed a spherical-like structure of TiO₂ NPs with various size distributions depending on the ablation period. It was also found that there is a relationship between laser ablation time and TiO₂ NP size distribution, where longer ablation times led to the smaller size distribution. The antibacterial activity of TiO₂ NPs was evaluated with different species of bacteria such as Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, and Staphylococcus aureus, using the liquid approach. The optimum activity of TiO₂ NPs is found to be against E. coli at 1000 μg mL⁻¹. Furthermore, adding, TiO₂ NPs (1000 μg mL⁻¹) in the presence of amoxicillin has a synergic effect on E. coli and S. aureus growth, as measured by the well diffusion method. However, both E. coli (11.6 ± 0.57mm) and S. aureus (13.3 ± 0.57mm) were inhibited by this process.